Control of micro- and nano- particles with electric and magnetic fields

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Creator

Spinella-Mamo, Vincent Paul.

Description

Thesis (Ph.D.)--Georgetown University, 2008.; Includes bibliographical references. This dissertation is presented in two sections. The first section encompasses the control of microparticles via the application of externally applied electric fields. It has previously been shown how electric fields can be employed to control and manipulate matter. Here, I show that cells can be controlled via electric fields using a mathematical description. Cells were chosen as the microparticle, as this phenomena can be employed in a device to manipulate and transfect cells. Once described mathematically, I have modeled the motion of these cells using a finite time step algorithm. Once the mathematical and physical modeling is complete, I have designed, fabricated, and tested one part of a device which will be employed for the specific purpose of manipulation and transfection of cells.; Magnetic fields have been shown to interact with matter in a similar manner. Using a similar construct as described above, the manipulation has been described mathematically and then modeled by introducing novel search and optimization algorithms. These techniques were applied to a ferrofluid system, which is a paramagnetic fluid comprised of nanoparticles of iron oxide surrounded by a surfactant. A possible application of ferrofluids under controlled magnetic fields relies on using the resulting local deformations in the paramagnetic fluid to alter the path of light for switching and optical projection techniques. This device has been designed, fabricated, and tested as well. In addition, a consequence of the device testing led to the development of a secondary application of the phenomenon. Another device has been developed and demonstrated that can produce variable channel widths using the ferrofluid and variations in the applied magnetic field.